| 摘要 |
PURPOSE:To simplify construction, to permit high-speed control and to decrease the light loss when attenuation control is not made by using a material having an electrooptic effect in an optical attenuation control part. CONSTITUTION:Three sides of a core part 1 having a rectangular section are enclosed by a clad part 2 and the optical attenuation control part 3 consisting of the material having the electrooptic effect is provided so as to contact the remaining one side. An electrode 4 is connected thereto. KDP (DK2PO4), KH2PO4, GaAs, etc., are used for the material having the electrooptic effect. Since the refractive index is changed and the continuous adjustment of the quantity of the optical attenuation can be made by energizing the electrode 4, the construction is simple and the high-speed control is possible. The light loss when the attention control is not made is decreased if the optical attenuation control part 3 and the clad part 2 are formed to have the same refractive index. |
